Stay-bolt structure for boilers.



J. n. FLANNERY & E. I. 00003.

STAY BOLT STRUCTURE FOR BOILERS. APPLICATION FILED JULY 31, I917.

Patented June 11, 1918 WITNESSES JOHN ROGERS FLANNERY AND BTHAN I. DODDS, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNORS TO FLANNERY BOLT COMPANY, OF PITTSBURGH, PENNSYLVANIA STAY-BOLT STRUCTURE FOR BOILERS.

Specification of Letters Patent.

Patented June 111, llgdd.

Application filed July 31, 1917. Serial No. 183,730.

To all whom it may concern:

Be it known that we, JOHN Roenns FLAN- NERY and ETHAN I. Donns, citizens of the United States, and residents of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Stay-Bolt Structures for Boilers; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in stay bolt structures for boilers and more particularly to means to permit the testing of said stay bolt,the object of the invention being to provide simple and eflicient means whereby the bolt may be easily tested to determine whether the same is ruptured and without the necessity of having access to the bore. of the bolt for this purpose.

With this object in view the invention consists in certain novel features of construction and combinations of parts as hereinafter set forth and pointed out in the claims.

In the accompanying drawing is illustrated an embodiment of our invention.

1 represents a stay bolt of the flexible type having a rounded head 2 at one end and havin its other end adapted for threaded connection with an inner boiler sheet 3. The bolt 1 is provided with a tell tale bore 4 which extends from the inner end of the bolt to and within the headed end 2 thereof.

The inner end of the bore 4 may be sealed by a plug 5 of fire clay or other suitable material and this plug holds in place a cup shaped cap 6 which may be of magnetic metal.

A rod 7 is disposed freely within the bore 4 and is of a length somewhat less than the distance between the metal cap 6 and the other end of said bore. The rod 7 is normally maintained in an intermediate position by means of springs 8 and 9 at respective ends thereof. The spring 8 may bear at one end against the cap 6 and at its other end against one end of a tube or envelop 10 which incloses the rod. 7. The spring 9 may bear at one end against the opposite end of said tube and at its other end against the .end wall of the boiler.

The tube 10 is composed of absorbent material and is of a diameter suflicient to approximately fill the bore 4. The absorbent material of which the tube is composed may consist of readily absorbent paper, so that in the event of rupture of the bolt, water entering the bore 4 willcause said absorbent tube to expand sufliciently to prevent longitudi nal movement of the rod 7.

Under normal onditions when the bolt is whole,.and an electromagnet 11 having its.

reciprocate and to strike the cap 6,the-

sound thus produced indicating that the bolt is whole. Should the bolt become ruptured so as toadmit moisture to the bore 4 and thus cause the tube '10 to expand and thereby bind the rod 7 within the bore, the appli cation of the magnet 11 would not cause the rod 7 to reciprocate and therefore said rod could not strike the cap 6. There would therefore be'no sound and this fact would denote that the bolt is ruptured.

Having fullydescrib'ed our invention what we claim as new and desire to secure by Letters-Patent, is:

1. Thecombination with a stay bolt having a bore, of a device confined and movable in said bore to provide an audible signal within the latter. 4

2. The combination with a stay bolt having a bore, of an audible signaling device within said bore, and means for preventing the operation of the signaling device when the bolt is ruptured.

3. The combination with a stay bolt having a bore, of a rod mounted to reciprocate in said bore, said rod being responsive to the IIIWLW 1,2 68,826

this specification in the presence of two subscribing witnesses.

JOHN ROGERS FLANNERY. ETHAN I. DODDS.

Witnesses:

EDWIN S. RYCE, F. H. ALmsoN. 

